If the macOS installer says this volume is not a supported Core Storage configuration

You may get this message after replacing the hard drive component of your Fusion Drive with an SSD.

Fusion Drive combines a hard drive and flash storage in a single volume for improved performance and storage capacity. If the hard drive component of your Fusion Drive was removed and replaced with an SSD (solid-state drive), your Mac is no longer using a supported Core Storage configuration.

To return to a supported configuration for Fusion Drive, replace the SSD with a conventional hard disk drive, then follow the steps to fix a split Fusion Drive. You can then install macOS on the Fusion Drive.